Twist-angle engineering in van der Waals homo- and hetero-bilayers introduces profound modifications in their electronic, optical, and mechanical properties due to lattice reconstruction. In these systems, the interlayer coupling and atomic rearrangement strongly depend on the twist angle, leading to the formation of periodic moiré superlattices. At small twist angles, significant lattice relaxation results in the emergence of domain structures separated by one-dimensional (1D) soliton networks, influencing electronic band structures and phonon modes. In this study, we systematically investigate the impact of lattice reconstruction on phonon renormalization in twisted bilayer graphene (TBLG) and graphene-hBN moiré superlattices, representing homo- and hetero-bilayer system, respectively. Using Raman spectroscopy, we identify distinct phonon behaviors across different twist angle regimes. In TBLG, we observe the evolution of the G peak, including broadening, splitting, and the emergence of additional peaks in the small angle range (0.3°−1°), attributed to moiré-modified phonon interactions. At large twist angles, the peaks gradually merge back into a single feature, reflecting the reduced impact of lattice reconstruction. Similarly, in hBN–graphene moiré superlattices, we detect moiré-induced Raman peaks above and below the G peak, while the central G peak remains largely invariant to twist angle variation. The theoretical calculations based on classical force-field uncover moiré phonon modes originating from different stacking regions, including AB (AB′), AA, and SP configurations, providing insights into phonon renormalization driven by lattice reconstruction. Our results establish a direct link between twist angle, lattice reconstruction, moiré phonons, and interlayer coupling, offering a fundamental framework for understanding phonon engineering in twisted bilayer systems. These findings pave the way for controlling phononic, optoelectronic, and heat flow properties in next generation van der Waals heterostructures.
由于晶格重构，范德华双分子层和异质双分子层的扭角工程对其电子、光学和机械性能产生了深远的影响。在这些体系中，层间耦合和原子重排强烈依赖于扭转角，导致周期莫尔维尔超晶格的形成。在小的扭转角下，显著的晶格弛豫导致一维孤子网络分离的畴结构出现，影响电子能带结构和声子模式。在这项研究中，我们系统地研究了晶格重构对双扭曲层石墨烯（TBLG）和石墨烯- hbn超晶格中声子重整化的影响，分别代表了同质层和异质层体系。利用拉曼光谱，我们确定了不同扭转角下不同声子的行为。在TBLG中，我们观察到G峰的演化，包括在小角度范围（0.3°~ 1°）内的展宽、分裂和出现额外的峰，这是由于莫伊莫尔变异体修饰的声子相互作用。在大的扭转角度下，峰逐渐合并回单个特征，反映了晶格重构的影响减小。类似地，在hbn -石墨烯莫尔超晶格中，我们在G峰上下检测到莫尔诱导的拉曼峰，而中央G峰基本保持不变。基于经典力场的理论计算揭示了来自不同堆叠区域的声子模式，包括AB (AB ')， AA和SP构型，为晶格重构驱动的声子重整化提供了见解。我们的研究结果建立了扭曲角、晶格重构、畸变声子和层间耦合之间的直接联系，为理解扭曲双层系统中的声子工程提供了一个基本框架。这些发现为控制下一代范德华异质结构的声子、光电和热流特性铺平了道路。
{"title":"Probing phonon modes in reconstructed twisted homo- and hetero-bilayer system","authors":"Sushil Kumar Sahu, Robin Bajaj, Syed Ummair Ali, Ajay Bhut, Roshan Jesus Mathew, Shinjan Mandal, Kenji Watanabe, Takashi Taniguchi, Manish Jain, Chandan Kumar","doi":"10.1063/5.0295168","DOIUrl":"https://doi.org/10.1063/5.0295168","url":null,"abstract":"Twist-angle engineering in van der Waals homo- and hetero-bilayers introduces profound modifications in their electronic, optical, and mechanical properties due to lattice reconstruction. In these systems, the interlayer coupling and atomic rearrangement strongly depend on the twist angle, leading to the formation of periodic moiré superlattices. At small twist angles, significant lattice relaxation results in the emergence of domain structures separated by one-dimensional (1D) soliton networks, influencing electronic band structures and phonon modes. In this study, we systematically investigate the impact of lattice reconstruction on phonon renormalization in twisted bilayer graphene (TBLG) and graphene-hBN moiré superlattices, representing homo- and hetero-bilayer system, respectively. Using Raman spectroscopy, we identify distinct phonon behaviors across different twist angle regimes. In TBLG, we observe the evolution of the G peak, including broadening, splitting, and the emergence of additional peaks in the small angle range (0.3°−1°), attributed to moiré-modified phonon interactions. At large twist angles, the peaks gradually merge back into a single feature, reflecting the reduced impact of lattice reconstruction. Similarly, in hBN–graphene moiré superlattices, we detect moiré-induced Raman peaks above and below the G peak, while the central G peak remains largely invariant to twist angle variation. The theoretical calculations based on classical force-field uncover moiré phonon modes originating from different stacking regions, including AB (AB′), AA, and SP configurations, providing insights into phonon renormalization driven by lattice reconstruction. Our results establish a direct link between twist angle, lattice reconstruction, moiré phonons, and interlayer coupling, offering a fundamental framework for understanding phonon engineering in twisted bilayer systems. These findings pave the way for controlling phononic, optoelectronic, and heat flow properties in next generation van der Waals heterostructures.","PeriodicalId":8200,"journal":{"name":"Applied physics reviews","volume":"415 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147393372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nuclear magnetic resonance (NMR) spectroscopy is widely used across chemistry, applied physics, life sciences, and related disciplines. As NMR studies grow in complexity, artificial intelligence (AI) has emerged as a transformative tool to improve NMR data acquisition, processing, and analysis, fundamentally reshaping conventional NMR workflows. This review provides a comprehensive overview of recent advances in AI-enabled NMR reconstruction, tracing its methodological evolution from early artificial neural networks and evolutionary algorithms to contemporary deep learning (DL) frameworks. Main applications are examined in detail, including sparse reconstruction, noise filtering and artifact suppression, Laplace NMR inversion, pure shift NMR, chemical exchange saturation transfer NMR, RF pulse generation and pulse sequence design, and nanoscale NMR, among others. For each of these applications, AI methodologies, design choices, key innovations, and publicly available data repositories are highlighted. Moreover, we also summarize and compare the technical implementations and quality assessment behind these applications. Finally, we discuss current challenges, including trade-off between signal preservation and artifact suppression, limited model generalizability to unseen data, the absence of online and uniform quality assessment metrics, and the scarcity of high-quality experimental datasets, and outline future directions encompassing advanced network architectures and training strategies, the development of foundation models for NMR reconstruction, uncertainty-aware modeling and quality assessment benchmarking platforms, and the establishment of open-source datasets. Collectively, the integration of AI addresses long-standing limitations in NMR spectroscopy and improves the quality of NMR spectra, enabling automated analysis of experimental data and enhancing subsequent spectral interpretation, thus providing the stronger support for scientific research and practical applications.
{"title":"Recent progress in artificial intelligence enabled NMR spectroscopy: Methodologies, implementations, quality assessments, and prospects","authors":"Haolin Zhan, Yuqing Huang, Zhong Chen","doi":"10.1063/5.0277355","DOIUrl":"https://doi.org/10.1063/5.0277355","url":null,"abstract":"Nuclear magnetic resonance (NMR) spectroscopy is widely used across chemistry, applied physics, life sciences, and related disciplines. As NMR studies grow in complexity, artificial intelligence (AI) has emerged as a transformative tool to improve NMR data acquisition, processing, and analysis, fundamentally reshaping conventional NMR workflows. This review provides a comprehensive overview of recent advances in AI-enabled NMR reconstruction, tracing its methodological evolution from early artificial neural networks and evolutionary algorithms to contemporary deep learning (DL) frameworks. Main applications are examined in detail, including sparse reconstruction, noise filtering and artifact suppression, Laplace NMR inversion, pure shift NMR, chemical exchange saturation transfer NMR, RF pulse generation and pulse sequence design, and nanoscale NMR, among others. For each of these applications, AI methodologies, design choices, key innovations, and publicly available data repositories are highlighted. Moreover, we also summarize and compare the technical implementations and quality assessment behind these applications. Finally, we discuss current challenges, including trade-off between signal preservation and artifact suppression, limited model generalizability to unseen data, the absence of online and uniform quality assessment metrics, and the scarcity of high-quality experimental datasets, and outline future directions encompassing advanced network architectures and training strategies, the development of foundation models for NMR reconstruction, uncertainty-aware modeling and quality assessment benchmarking platforms, and the establishment of open-source datasets. Collectively, the integration of AI addresses long-standing limitations in NMR spectroscopy and improves the quality of NMR spectra, enabling automated analysis of experimental data and enhancing subsequent spectral interpretation, thus providing the stronger support for scientific research and practical applications.","PeriodicalId":8200,"journal":{"name":"Applied physics reviews","volume":"8 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147393190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chengmei Gui, Zhenni Liu, Yutong Wang, Zhaoyan Zhu, Chao Li, Xingke Zhao, Jun Chen, Tao Jiang, Zhanyong Hong, Junjun Huang
Triboelectric nanogenerator (TENG)-based sensors have emerged as transformative technologies for energy harvesting and self-powered sensing. Enhancing the waveform characteristics of triboelectric signals is crucial for improving sensing accuracy. Here, we report a TENG-based vibration sensor employing a polymer-encapsulated metal conductor, guided by a unique one- and two-dimensional composite structural interface to enrich signal waveform features. An ethyl cellulose-modified electroless copper-plated nonwoven substrate was used as the inner electrode, subsequently encapsulated in a low-modulus polydimethylsiloxane (PDMS) matrix to fabricate the device. Upon contact with external stimuli, including vibration waves and diverse material surfaces, the overlap of electron clouds at the electrode/PDMS interface reduces the energy barrier, facilitating electron transfer and generating triboelectric signals. Notably, the multidimensional electrode structure produces signals with richer, subtle features, which can be effectively captured by machine learning algorithms to extract detailed information about the stimuli. This work provides an innovative approach for enhancing triboelectric waveform features and demonstrates a high-accuracy tactile sensor with potential for advancing sustainable and intelligent sensing technologies.
{"title":"Unveiling the waveform feature enhancement strategy of a triboelectric signal by exploring a unique one- and two-dimensional composite structural interface","authors":"Chengmei Gui, Zhenni Liu, Yutong Wang, Zhaoyan Zhu, Chao Li, Xingke Zhao, Jun Chen, Tao Jiang, Zhanyong Hong, Junjun Huang","doi":"10.1063/5.0312315","DOIUrl":"https://doi.org/10.1063/5.0312315","url":null,"abstract":"Triboelectric nanogenerator (TENG)-based sensors have emerged as transformative technologies for energy harvesting and self-powered sensing. Enhancing the waveform characteristics of triboelectric signals is crucial for improving sensing accuracy. Here, we report a TENG-based vibration sensor employing a polymer-encapsulated metal conductor, guided by a unique one- and two-dimensional composite structural interface to enrich signal waveform features. An ethyl cellulose-modified electroless copper-plated nonwoven substrate was used as the inner electrode, subsequently encapsulated in a low-modulus polydimethylsiloxane (PDMS) matrix to fabricate the device. Upon contact with external stimuli, including vibration waves and diverse material surfaces, the overlap of electron clouds at the electrode/PDMS interface reduces the energy barrier, facilitating electron transfer and generating triboelectric signals. Notably, the multidimensional electrode structure produces signals with richer, subtle features, which can be effectively captured by machine learning algorithms to extract detailed information about the stimuli. This work provides an innovative approach for enhancing triboelectric waveform features and demonstrates a high-accuracy tactile sensor with potential for advancing sustainable and intelligent sensing technologies.","PeriodicalId":8200,"journal":{"name":"Applied physics reviews","volume":"23 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147314865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Solid-state cooling based on caloric effects offers a promising and sustainable refrigeration solution. However, developing barocaloric materials that combine a large thermal response with high mechanical ductility remains challenging. Here, we report a giant barocaloric effect in superionic-ductile Ag2S-based thermoelectric semiconductors, achieved through medium-entropy alloying (Ag2S1-x-ySexTey). This yields a colossal barocaloric strength of ∼0.41 J kg−1 K−1 MPa−1 near room temperature, enabled by a large entropy change (∼42 J kg−1 K−1) under a low driving pressure of ∼100 MPa. In situ neutron and x-ray diffraction reveal a reversible pressure-driven order–disorder transition of the Ag-ion sublattice, with diffuse scattering confirming the giant configurational entropy change. Simultaneously, the material's inherently exceptional plasticity (compression >90%, stretching ∼43%, and bending >100%) ensures excellent cyclability, with a stable adiabatic temperature change of ∼4.8 K and negligible performance drift during repeated cycling. This work synergizes mechanical ductility with superionic entropy engineering, establishing a robust platform for efficient, durable barocaloric cooling and expanding the functional scope of thermoelectrics as versatile solid-state refrigerants.
{"title":"Giant yet robust barocaloric cooling in superionic-ductile Ag2S thermoelectrics","authors":"Xiao-Ming Huang, Xiaowen Hao, Tingjiao Xiong, Yifan Yuan, Ziqi Guan, Xiaoli Huang, Hongliang Dong, Jinfu Shu, Le Kang, Bao Yuan, Dexiang Gao, Xudong Shen, Cuiping Zhang, Guoliang Li, Bing Li, Peng Tong, Kunpeng Zhao, Xin Tong, Qingyong Ren","doi":"10.1063/5.0312529","DOIUrl":"https://doi.org/10.1063/5.0312529","url":null,"abstract":"Solid-state cooling based on caloric effects offers a promising and sustainable refrigeration solution. However, developing barocaloric materials that combine a large thermal response with high mechanical ductility remains challenging. Here, we report a giant barocaloric effect in superionic-ductile Ag2S-based thermoelectric semiconductors, achieved through medium-entropy alloying (Ag2S1-x-ySexTey). This yields a colossal barocaloric strength of ∼0.41 J kg−1 K−1 MPa−1 near room temperature, enabled by a large entropy change (∼42 J kg−1 K−1) under a low driving pressure of ∼100 MPa. In situ neutron and x-ray diffraction reveal a reversible pressure-driven order–disorder transition of the Ag-ion sublattice, with diffuse scattering confirming the giant configurational entropy change. Simultaneously, the material's inherently exceptional plasticity (compression >90%, stretching ∼43%, and bending >100%) ensures excellent cyclability, with a stable adiabatic temperature change of ∼4.8 K and negligible performance drift during repeated cycling. This work synergizes mechanical ductility with superionic entropy engineering, establishing a robust platform for efficient, durable barocaloric cooling and expanding the functional scope of thermoelectrics as versatile solid-state refrigerants.","PeriodicalId":8200,"journal":{"name":"Applied physics reviews","volume":"152 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147292381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Flexible piezoelectric composite thin films have emerged as a transformative platform for next-generation self-powered electronics, soft robotics, and biomedical devices, overcoming the inherent rigidity of traditional ceramics and the limited piezoelectric response of polymers. This comprehensive review systematically examines the significant breakthroughs of the past decade, focusing on synergistic advancements in material innovation and performance optimization. It explores the development of ultrahigh-performance lead-based systems and the substantial progress in eco-friendly lead-free alternatives, including textured ceramics, perovskite derivatives, and two-dimensional materials. The article further details how structural engineering—through architectures such as vertically aligned arrays and multilayer heterostructures—enhances stress transfer and electromechanical coupling. Critical strategies to overcome fundamental limitations are analyzed, encompassing interfacial modifications, self-poling mechanisms, and the burgeoning role of machine learning in accelerating material discovery. The application spectrum spanning wearable sensors, implantable harvesters, and industrial IoT systems is reviewed, highlighting the translation of laboratory innovations toward practical deployment. Finally, persistent challenges and strategic future directions are outlined, emphasizing the need for sustainable materials, hybrid energy systems, and scalable manufacturing to fully realize the potential of intelligent, autonomous piezoelectric technologies.
{"title":"Recent advances in flexible piezoelectric composite thin films: Material innovations and performance optimization","authors":"Hailin Wang, Suzhu Yu, Jun Wei","doi":"10.1063/5.0299695","DOIUrl":"https://doi.org/10.1063/5.0299695","url":null,"abstract":"Flexible piezoelectric composite thin films have emerged as a transformative platform for next-generation self-powered electronics, soft robotics, and biomedical devices, overcoming the inherent rigidity of traditional ceramics and the limited piezoelectric response of polymers. This comprehensive review systematically examines the significant breakthroughs of the past decade, focusing on synergistic advancements in material innovation and performance optimization. It explores the development of ultrahigh-performance lead-based systems and the substantial progress in eco-friendly lead-free alternatives, including textured ceramics, perovskite derivatives, and two-dimensional materials. The article further details how structural engineering—through architectures such as vertically aligned arrays and multilayer heterostructures—enhances stress transfer and electromechanical coupling. Critical strategies to overcome fundamental limitations are analyzed, encompassing interfacial modifications, self-poling mechanisms, and the burgeoning role of machine learning in accelerating material discovery. The application spectrum spanning wearable sensors, implantable harvesters, and industrial IoT systems is reviewed, highlighting the translation of laboratory innovations toward practical deployment. Finally, persistent challenges and strategic future directions are outlined, emphasizing the need for sustainable materials, hybrid energy systems, and scalable manufacturing to fully realize the potential of intelligent, autonomous piezoelectric technologies.","PeriodicalId":8200,"journal":{"name":"Applied physics reviews","volume":"57 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147292380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiangtian Xiao, Dadi Tian, Fumin Lu, Chuangping Liu, Xiaoli Zhang, Dan Wu, Xiao Wei Sun, Kai Wang
Quantum dot light-emitting diodes (QLEDs) are promising for light sources in visible light communications due to their solution-processability and chip integration capability. The equivalent circuit model is a typical method to analyze modulation bandwidth for QLEDs, but it only describes electrical behavior, failing to quantify electro-optical conversion, and hindering the identification of the main factors limiting modulation bandwidth of QLEDs. This serious issue prevents further improvement of QLED modulation bandwidth under theoretical guidance. This study proposes an electro-optical coupled model integrating electro-optical conversion (equated to a low-pass filter) into the equivalent circuit. The model reflects comprehensive physical processes, shows high consistency with experimental results. We identify the electroluminescence decay time as the main bottleneck limiting the bandwidth. Targeted optimizations significantly improve modulation bandwidth from 1.57 to 8.04 MHz, providing actionable guidelines for QLEDs with high modulation bandwidth.
{"title":"Revealing the main limiting factors of modulation bandwidth in quantum dot light-emitting diodes through an electro-optical coupled modulation model","authors":"Xiangtian Xiao, Dadi Tian, Fumin Lu, Chuangping Liu, Xiaoli Zhang, Dan Wu, Xiao Wei Sun, Kai Wang","doi":"10.1063/5.0313518","DOIUrl":"https://doi.org/10.1063/5.0313518","url":null,"abstract":"Quantum dot light-emitting diodes (QLEDs) are promising for light sources in visible light communications due to their solution-processability and chip integration capability. The equivalent circuit model is a typical method to analyze modulation bandwidth for QLEDs, but it only describes electrical behavior, failing to quantify electro-optical conversion, and hindering the identification of the main factors limiting modulation bandwidth of QLEDs. This serious issue prevents further improvement of QLED modulation bandwidth under theoretical guidance. This study proposes an electro-optical coupled model integrating electro-optical conversion (equated to a low-pass filter) into the equivalent circuit. The model reflects comprehensive physical processes, shows high consistency with experimental results. We identify the electroluminescence decay time as the main bottleneck limiting the bandwidth. Targeted optimizations significantly improve modulation bandwidth from 1.57 to 8.04 MHz, providing actionable guidelines for QLEDs with high modulation bandwidth.","PeriodicalId":8200,"journal":{"name":"Applied physics reviews","volume":"9 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147292378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dengyang Guo, Alan R. Bowman, Sebastian Gorgon, Changsoon Cho, Young-Kwang Jung, Jiashang Zhao, Linjie Dai, Jaewang Park, Kyung Mun Yeom, Satyawan Nagane, Stuart Macpherson, Weidong Xu, Jun Hong Noh, Sang Il Seok, Tom Savenije, Samuel D. Stranks
Halide perovskite solar cells have demonstrated a rapid increase in power conversion efficiencies. Understanding and mitigating remaining carrier losses in halide perovskites is now crucial to enable further increases to approach their practical efficiency limits. Recent observations in halide perovskites have revealed processes such as shallow carrier trapping, which give rise to an apparent non-radiative bimolecular channel that is difficult to distinguish from intrinsic radiative recombination. Here, we quantify this shallow-trap manifestation by jointly analyzing time-resolved photoluminescence and quantum efficiency to separate the total second-order term into radiative (ηesck2r) and shallow-trap-mediated non-radiative contributions (k2non), and evaluate their device impact. We show that k2non is strongly modulated by temperature and surface chemistry and thus depends on extrinsic factors and its origin is independent from deep traps, whereas the intrinsic radiative coefficient and intrinsic second-order recombination follow detailed-balance expectations and align with theoretical evaluations through van Roosbroeck–Shockley relations. Based on density functional theory simulations and Quasi-Fermi level calculations, we propose that surface states are the primary origin of this shallow-trap-related second-order component, contributing up to ∼80 mV of the overall reduction in Voc at room temperature. This work reveals that the origin of carrier losses from two non-radiative recombination types (first and second order) are not linked, emphasizing the need for distinctive mitigation strategies targeting each type to unlock the full efficiency potential of perovskite solar cells.
{"title":"Modulating non-radiative recombination related to shallow traps in halide perovskites","authors":"Dengyang Guo, Alan R. Bowman, Sebastian Gorgon, Changsoon Cho, Young-Kwang Jung, Jiashang Zhao, Linjie Dai, Jaewang Park, Kyung Mun Yeom, Satyawan Nagane, Stuart Macpherson, Weidong Xu, Jun Hong Noh, Sang Il Seok, Tom Savenije, Samuel D. Stranks","doi":"10.1063/5.0279622","DOIUrl":"https://doi.org/10.1063/5.0279622","url":null,"abstract":"Halide perovskite solar cells have demonstrated a rapid increase in power conversion efficiencies. Understanding and mitigating remaining carrier losses in halide perovskites is now crucial to enable further increases to approach their practical efficiency limits. Recent observations in halide perovskites have revealed processes such as shallow carrier trapping, which give rise to an apparent non-radiative bimolecular channel that is difficult to distinguish from intrinsic radiative recombination. Here, we quantify this shallow-trap manifestation by jointly analyzing time-resolved photoluminescence and quantum efficiency to separate the total second-order term into radiative (ηesck2r) and shallow-trap-mediated non-radiative contributions (k2non), and evaluate their device impact. We show that k2non is strongly modulated by temperature and surface chemistry and thus depends on extrinsic factors and its origin is independent from deep traps, whereas the intrinsic radiative coefficient and intrinsic second-order recombination follow detailed-balance expectations and align with theoretical evaluations through van Roosbroeck–Shockley relations. Based on density functional theory simulations and Quasi-Fermi level calculations, we propose that surface states are the primary origin of this shallow-trap-related second-order component, contributing up to ∼80 mV of the overall reduction in Voc at room temperature. This work reveals that the origin of carrier losses from two non-radiative recombination types (first and second order) are not linked, emphasizing the need for distinctive mitigation strategies targeting each type to unlock the full efficiency potential of perovskite solar cells.","PeriodicalId":8200,"journal":{"name":"Applied physics reviews","volume":"14 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147292223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Muhammad Rizwan Khan, Ghulam Hussain, Jin Yang, Xiaoguang Li, Jincheng Kong, Zheng Wang
The search for new quantum material phases has long been a major focus in condensed matter physics and materials science due to their intriguing physics and potential applications. Recently, a new class of multi-functional quantum materials has been emerged that combines the characteristic traits of both metals and insulators, known as gapped metals. These materials hold the Fermi level within the conduction or valence band and an internal bandgap between principal band edges. Owing to their high intrinsic conductivity and internal bandgap, these materials are considered as a promising substitute for heavily doped semiconductors without external doping. They exhibit potential for high-performance thermoelectric, transparent conducting, photocatalytic, and nano-electronic devices. Furthermore, gapped metals display properties resembling electrides, topological materials, and even dilute magnetic semiconductors without intentional transition-metal doping, due to their spin-dependent band gaps. Their intrinsic carrier concentration and internal bandgap can be tailored via spontaneous non-stoichiometry, enabling tunable functionalities. Motivated by these unique characteristics and promising applications, this review comprehensively examined the recent theoretical and experimental progress on gapped metals, highlighted their potential applications, elucidated their distinct physical properties, and outlined the future directions for their usages in the development of advanced technologies.
{"title":"Exploring gapped metals: An emerging class of multi-functional quantum materials","authors":"Muhammad Rizwan Khan, Ghulam Hussain, Jin Yang, Xiaoguang Li, Jincheng Kong, Zheng Wang","doi":"10.1063/5.0308115","DOIUrl":"https://doi.org/10.1063/5.0308115","url":null,"abstract":"The search for new quantum material phases has long been a major focus in condensed matter physics and materials science due to their intriguing physics and potential applications. Recently, a new class of multi-functional quantum materials has been emerged that combines the characteristic traits of both metals and insulators, known as gapped metals. These materials hold the Fermi level within the conduction or valence band and an internal bandgap between principal band edges. Owing to their high intrinsic conductivity and internal bandgap, these materials are considered as a promising substitute for heavily doped semiconductors without external doping. They exhibit potential for high-performance thermoelectric, transparent conducting, photocatalytic, and nano-electronic devices. Furthermore, gapped metals display properties resembling electrides, topological materials, and even dilute magnetic semiconductors without intentional transition-metal doping, due to their spin-dependent band gaps. Their intrinsic carrier concentration and internal bandgap can be tailored via spontaneous non-stoichiometry, enabling tunable functionalities. Motivated by these unique characteristics and promising applications, this review comprehensively examined the recent theoretical and experimental progress on gapped metals, highlighted their potential applications, elucidated their distinct physical properties, and outlined the future directions for their usages in the development of advanced technologies.","PeriodicalId":8200,"journal":{"name":"Applied physics reviews","volume":"18 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146204868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In modern quantum technologies, quantum emitters (QEs) have emerged as core components of quantum communication networks and on-chip quantum information processing, representing a pivotal link in future quantum systems. Due to atomic-scale thickness, the absence of dangling bonds at interfaces, and surface-localized photonic states that facilitate efficient light–matter interactions, two-dimensional (2D) materials are considered ideal platforms for high-performance, wavelength-tunable, and on-chip integrable solid-state QEs. While QEs have been demonstrated in various 2D materials, several challenges and unresolved issues remain. This review systematically summarizes the latest advances in the research of QEs based on 2D materials, aiming to provide comprehensive introductory guidance for beginners or interested readers. We first outline the fundamentals of single-photon emission, including basic principles, performance metrics, and experimental characterization methods. A comprehensive survey of cutting-edge studies on QEs based on hexagonal boron nitride, transition metal dichalcogenides, and twisted moiré heterostructures is presented, highlighting emission mechanisms and structure–luminescence correlations. Furthermore, we summarize strategies for creating and localizing QEs through external field engineering in 2D systems, tuning emission wavelengths, and enhancing emission performance, including wavelength tuning and emission enhancement techniques. Finally, current challenges are analyzed, and perspectives for advancing scientific exploration in this field are proposed. Leveraging their unique physical properties and integration potential, these 2D QEs hold great promise for quantum information technologies, communication systems, and various interdisciplinary fields.
{"title":"Quantum emitters based on 2D materials: Progress and prospects","authors":"Hao Zhou, Ting Wang, Hongliang Li, Xiaoran Wang, Junyong Wang, Gaolei Zhan, Baiquan Liu, Junhong Yu, Xuechao Yu, Kai Zhang","doi":"10.1063/5.0282350","DOIUrl":"https://doi.org/10.1063/5.0282350","url":null,"abstract":"In modern quantum technologies, quantum emitters (QEs) have emerged as core components of quantum communication networks and on-chip quantum information processing, representing a pivotal link in future quantum systems. Due to atomic-scale thickness, the absence of dangling bonds at interfaces, and surface-localized photonic states that facilitate efficient light–matter interactions, two-dimensional (2D) materials are considered ideal platforms for high-performance, wavelength-tunable, and on-chip integrable solid-state QEs. While QEs have been demonstrated in various 2D materials, several challenges and unresolved issues remain. This review systematically summarizes the latest advances in the research of QEs based on 2D materials, aiming to provide comprehensive introductory guidance for beginners or interested readers. We first outline the fundamentals of single-photon emission, including basic principles, performance metrics, and experimental characterization methods. A comprehensive survey of cutting-edge studies on QEs based on hexagonal boron nitride, transition metal dichalcogenides, and twisted moiré heterostructures is presented, highlighting emission mechanisms and structure–luminescence correlations. Furthermore, we summarize strategies for creating and localizing QEs through external field engineering in 2D systems, tuning emission wavelengths, and enhancing emission performance, including wavelength tuning and emission enhancement techniques. Finally, current challenges are analyzed, and perspectives for advancing scientific exploration in this field are proposed. Leveraging their unique physical properties and integration potential, these 2D QEs hold great promise for quantum information technologies, communication systems, and various interdisciplinary fields.","PeriodicalId":8200,"journal":{"name":"Applied physics reviews","volume":"98 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146160143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Inhibiting Leidenfrost effect to enhance heat transfer is crucial yet a formidable challenge, particularly at extremely high temperatures. Previously, we developed a heterogeneous structural thermal armor (STA) that fundamentally inhibits Leidenfrost effect even over 1000 °C by integrating thermally insulating porous membranes into thermally conductive metal pillars. Despite this, there are still some unrevealed mechanisms underlying the efficient heat transfer of heterogeneous STA that are beyond the current experimental capacity, as exemplified by the invisible formation of vapor layer. Herein, we extended the understanding of heat transfer of STA by conducting a theoretical simulation using a combination of the volume of fraction model and the Lee phase change model. We revealed the critical role of surface free energy of porous membrane in promoting wettability, evaporation, and particularly the vapor evacuation dynamics of heterogeneous STA. This work not only advances our fundamental understanding of Leidenfrost effect inhabitation but also provides insight on designing heterogeneous STA with optimal heat transfer efficiency.
{"title":"Theoretically revisiting structural thermal armor for efficient Leidenfrost effect inhabitation","authors":"Mingyu Li, Wei Wang, Mengnan Jiang, Huaduo Gu, Yuchao Li, Hangchen Liu, Penghao Duan, Baoping Zhang, Zuankai Wang","doi":"10.1063/5.0291834","DOIUrl":"https://doi.org/10.1063/5.0291834","url":null,"abstract":"Inhibiting Leidenfrost effect to enhance heat transfer is crucial yet a formidable challenge, particularly at extremely high temperatures. Previously, we developed a heterogeneous structural thermal armor (STA) that fundamentally inhibits Leidenfrost effect even over 1000 °C by integrating thermally insulating porous membranes into thermally conductive metal pillars. Despite this, there are still some unrevealed mechanisms underlying the efficient heat transfer of heterogeneous STA that are beyond the current experimental capacity, as exemplified by the invisible formation of vapor layer. Herein, we extended the understanding of heat transfer of STA by conducting a theoretical simulation using a combination of the volume of fraction model and the Lee phase change model. We revealed the critical role of surface free energy of porous membrane in promoting wettability, evaporation, and particularly the vapor evacuation dynamics of heterogeneous STA. This work not only advances our fundamental understanding of Leidenfrost effect inhabitation but also provides insight on designing heterogeneous STA with optimal heat transfer efficiency.","PeriodicalId":8200,"journal":{"name":"Applied physics reviews","volume":"11 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2026-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146160142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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